Pile foundations are generally classified as columnar structures. This format is recommended for the construction of low-rise buildings no higher than two stories. They are also installed on soft soils with high groundwater levels or for foundations on slopes. This format can be used to build foundations for bathhouses, residential buildings, outbuildings, and other structures. The basic difference between piers and piles in foundations is that in the former, the piles are installed on a prepared excavation surface, while in the latter, the material is driven directly into the ground.

Features and types of material for pile foundations

Piles made of various materials can be used in construction work—concrete, reinforced concrete, or wood. Metal piles are also available. Concrete has high load-bearing properties and is versatile, as it can be used on any soil. For pile installation, the following types of material are commonly used:

• Screw piles: These are driven into the ground like screws using specialized equipment. The driving depth can vary, but they often have at least one helical blade.
• Driven piles made of reinforced concrete: These are driven into the ground using a hydraulic hammer.
• Drilled piles: These are drilled on-site to install supports, which are then filled with concrete.
• Pressed piles: In this case, the pile foundation is driven into the ground using a hydraulic pump.

The classification also includes the location and number of piles required for the house. In this case, it's important to distinguish between multi-pile, single-pile, strip, and solid installations.

How to install a pile foundation

The work process varies depending on the type of material and the installation method. The following steps are involved in installing bored piles:

• Drilling boreholes. This work is performed using a gasoline or electric drill. The borehole diameter is approximately 30 cm, and the depth is up to 5 m.
• Formation of pile formwork. A 2-3-layer roofing felt structure is constructed, corresponding to the borehole diameter and 20-30 cm longer. This formwork is lowered into the borehole to accommodate the concrete pouring. Alternatively, asbestos-cement pipe of the required diameter can also be used.
• Reinforcement of the pile. The frame is made of reinforcing bars with a diameter of 6-8 mm. The piles are tied every 500-600 mm, with the frame extending to the full depth of the borehole. The upper part should extend to the level of the grillage.
• Concreting. The prepared concrete is fed into the borehole in layers, compacted with a vibrator or ramming. The process itself must be continuous, otherwise the concrete will not form the required monolith at the points of contact. Heavyweight concrete is used in this process, with quartz sand and 20mm crushed stone used as aggregates.
• Construction of the grillage. It can be deepened or shallow. In the shallow case, a small trench must be dug between the piles along the perimeter of the structure. A sand cushion is formed and compacted in this trench, and crushed stone is poured on top of this. Construction of a shallow grillage follows the same principle, but without digging a trench. The sand cushion is poured on top of the formwork, and then the process continues in the same manner.

The cost of constructing a pile foundation

The following factors influence the cost of a foundation:

• material type and price per pile;
• project size, which determines the scope of work;
• chosen pile installation technology;
• quantity of materials used;
• installation time;
• service type – turnkey or other.

This type of work requires a professional approach, as the "fate" of the building will depend on the quality of the foundation. To build a reliable and sturdy house on a solid foundation, it is necessary to have a thorough understanding of many aspects, including soil analysis and the specifics of pile construction. Furthermore, accurate pile foundation calculations are essential for accurate work, which is impossible without experience. Therefore, if you need to begin construction, it is best to contact RСC ALBA, a specialized construction company offering turnkey pile installation services.